Telephone



e W. GILLBTT.

TELEPHGNB.

. 296,829. Patented Apr. 15, 1884.

N4 PETERS. Phnm-umngnpmn wmgmn. D. c

Unirse @rares dernier @erica VEBSTER- GILLETT, OF FLUSHING, NEW YORK, ASSIGNOR TO THE ATLANTIC AND PACIFIC TELEPHONE COMPANY, OF SACO, IiIAINE.

TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 296,829, dated April 15I 1884.

Application filed October 15, 1883. Y (No model.)

To all. whom t may concern.-

Beit known that WEnsrnR GILLET-r, of Flushing, Queens county, in the State of New York, have invented certain new and useful Improvements relating to Telephones, of

which the following is a speoication.

This invention relates to telephones or apparatus for reproducing articulate sounds at distant points by the aid of electricity. I emro ploy a series of independent telephonie transmitting devices operated by one and the same action of the voice, and all contributing to the effect produced at the other end of the line. lI Willshow four 'sets of these parts; but it must be understood that I am not confined to four.

I can. use a larger number. A less numberas three-may serve with some success. I mount a series of pairs of electrodes near each other, and in contactwith a rigid piece receiving motion from adiaphragm. The rigid piece .may be a concave disk iirmly Xed' by its center to the center of the ordinary vibrating diaphragm. It communicates the motion of that point to a series of pins, which, delicately mounted and adjusted, each serve as one of the electrodes. I insulate the arms on which these are mounted, and make independent connections from each arm to its proper inductioncoil'.V I control the series of local batteries, 3o each operating its proper induction-coil, by a Asingle switch operating a single Wire properly connected tothe Whole. I make one groundwire,with suitable connections, serve for the Whole series of induction-Wires, each receiv ing its proper current from an independent induction-coil The following is adescription of what I consider the best means of carrying out the invention.

The accompanying drawings form a part of this specification.

Figure l is an elevation of the transmitter, showing the interior or back face. Fig. 2 is a section on the line a; .fc in Fig. 1. This shows one of the adjustable cylinders and adjacent parts in elevation. Fig. 3is a section through the cylinder and immediately adjacent parts, on a larger scale. Figa is a section on the line y y in Fig. l, on the same scale as Fig. 3.

Fig. 5 is a diagram 4of the instruments vvith 5o their connecting-wires, batteries, and groundconnections.

Similar letters of reference indicate corresponding parts in all the iigures Where they occur.

In the transmitter, Figs. l to 4, A is a mouthpiece tted in a board, A, in rear of which is mounted a diaphragm, I3, firmly clamped by a ring, D3. To the middle of the diaphragm B is connected a concave disk, B', rmly se- 6o cured to the diaphragm by a screw, B2. The disk B partakes of all the movements of the center of the diaphragm. To the ring D3 are rigidly secured by screws D four arms, D, each separated from the ring D3 by insulators 6 5 D2, of hard rubber or other non-conducting substance.- Anfire, d, makes an electrical connection between each arm D and the negative pole of a battery, L. The arms D extend inward until they nearly touch each other. inner end of each is screw-threaded to match the scrervthreaded exterior of a cylinder, G, inserted therein, which is provided with an enlarged head or Wheel, G', in which are bored holes adapted to receive a lever, (not represented,) by which it can be turned to adjust it with any degree of nicety in its bearings in the arm D. The interior of each cylinder G is equipped with two disks ofsoftvulcanized rubber or analogous material,I I", between which is 8o imprisoned a quantity of granulated gas-carbon, J, or other substance of high resistance, having preferably a iineness about equal to ordinary ridepowder. The disk I is tight. The disk I is perforated in the line of its axis, and receives a pin, E, having an enlargement or head,which, when the pin is pressed home, bears firmly against the outer face of thedisk I, with the other end of the pin extending a little distance into the powder J. The disk I is firmly pressed home in the cylinder by means of an internally-flanged and threaded thimble, G2. A conducting-Wire, e, connects the head of each pin E with the positive pole of the same battery, which connects, bythe Wire d, to the arm D. It follows that there is a circuit' from the battery through the Wires d e, which is obstructed. by its difficult passage from the pin E through the granulated carbon J to the interior of the cylinder G. The force of this current will vary with every iiuctuation in the conductivity. A variable pressure exerted on the head of the pin E will induce aiuctuation in the force of the current, for two reasons: The pin E will be thrust farther in and withdrawn, thus increasing and diminishing the amount of surfaces in contact between the pin E and the powder J. rIhis is one means by which the conductivity is`varied. Furthermore, the shoulder formed by the head of the pin E rests fairly against the outer face of the soft-rubber disk I, and every variation in the pressure on the pin will be transmitted through the disk and felt by the powder J. Each variation in the pressure on the powder changes its conductivity. This is the second means by which the conductivity is varied. These two fluctuations operate always in the same direction to re-enforce each other, An increased pressure on the head of the pin E results in both an increased pressure on the powder J, and also in athrusting of the pin El deeper into the powder, and a diminution of pressure on the head of the pin E resultsina diminution of pressure on the powder J and thepartial withdrawal of the pin E from the powder, so as to diminish the surfaces in contact. The parts are so proportioned that the heads of the pins E are presented near the periphery ofthe concave disk B. In adjusting the apparatus the lcylinders G are turned around, so that bythe engagement of their screw-threaded surfaces in the arms D they are set so that the head of each pin E makes the delicate contact with the disk B', sometimes known as telephonie contact.77 When a word isl spokeninto the mouth-piece A and vibrates the diaphragm B, the vibrations of the center of the diaphragm are communicated through the concave disk B equally to all the pins E, and, by the two means described,'in duce fluctuations in the force of the current through each of the four sets of wires d e.'

An induction-spool, F, is included in each circuit. The induction-coils may be of the ordinary construction, a coarse insulated wire being wound around a core of soft-iron wires carrying the primary current from the connected battery L, while a fine insulated wire wound exterior thereto is ready to transmit, through suitable connections, the secondary current, which is produced in this closely-associated fine wire by what is known as induction,77 at each iiuctuation in the force of the primary current. To the two ends of the induction-coil, which is wound in the usual way on the induction-spool F, are connected two conducting-wires, f h. Either of these wires f h may, by connecting one with the .earth and the other with the line M, serve to transmit its current over the line and induce vibrations at the other end. All four sets communicate simultaneously the same signals. I arrange for combining them and sending the united effect of the four over the same linewire.

F is the ground-plate at 'the transmitting end of the line. f is a single-wire leading 'therefrom to the vicinity of the instrument,

where it is connected by switch-plugs C with the several wires f leading to the four induction-spools F. K is the ground-plate at the opposite end of the line. 7c is a single wire, connecting from K, through the receiving-instrument and through the line M, to the vicinity of the transmitting-instrument, where it is connected to each of the four wires h leading back to the induction-coils in the respective induction-spools F. A connection Very similar to this is made with the primary currents. The primary currents, through the batteries L and their respective wires d e, pass at one point through a single wire, e3, so that a single switch-plug7 C, may connect and disconnect the whole at once. The arrangement to effect this is indieatedin Fig. 6, where the four wires e leading from the four primary coils in the spools F are united by a short cross-wire, c, to a single wire, e, which connects through'the switch-plug C to a longer single wire, es, which in its turn is connected to four short wires, e, leading to the positive poles of the several batteries L. The batteries are all connected to the induction-coils in the same manner and direction, and the induction-coils are all wound in the same direction relatively to each other.

Having thus described my invention and in what manner the same is to be performed, I claim as my invention the following improvements in teleplionesl I. In a telephone, the combination of a series of separate pins, E, connected with the carbon powder J to form a variable-resistance device, and the concave disk B', fixed to a point in the vibrating disk B, whereby simultaneous vibration may be communicated to said pins, substantially as set forth.

2. In combination with the variable-resistance device formed by the pins E and carbon powder J and the arms D, carrying the variable-resistance devices, the electrical connections d e, the disk B, and the diaphragm B, substantially as and for the purposes specified.

3. In a telephone, the cylinders G, carrying carbon powder J and engaging screwthreads in the arms D, the pins E,- and the disks B and B', the parts'J and E forming a variable-resistance device, which may be regulated by turning the cylinder G, substantially as specified.

In testimony whereof I have hereunto set my hand, at N ew York city, New York, this 20th day of September, 1883, in thepresence of two subscribing witnesses.

wEBsrER GILLETT.

'Witnesses:

W. C. DEY, OHARLEs R. SEARLE.

IOO 

